Congenital Cornification Disorder / ILVEN / Verrucous epidermal nevi (NSDHL-related) - Chihuahua

What does this test detect?

This genetic test analyses two NSDHL variants used in Chihuahuas for Congenital Cornification Disorder with an ILVEN-like skin phenotype: c.700G>A and c.718_722delGAACA.

Other names for this condition

The condition is also described as congenital disorder of cornification, ILVEN, inflammatory linear verrucous epidermal nevus, verrucous epidermal keratinocytic nevi, CHILD-like nevi or NSDHL-related genodermatosis.

What does this mean for the dog?

NSDHL is involved in cholesterol biosynthesis, a process important for normal skin development. Affected dogs may develop linear, thickened, wart-like and scaly plaques, often in zones or along skin developmental lines. The lesions can be persistent, itchy, painful, malodorous or secondarily infected. Severe paw pad cornification may also make standing and walking difficult.

Inheritance and result

These NSDHL variants follow X-linked incomplete dominant inheritance. Heterozygous female dogs are most likely to show the mosaic skin phenotype. Male animals carrying the variant are generally not expected to be viable, so the result is interpreted differently from a simple autosomal recessive carrier test.

Practical value of this test

• The test helps breeders check two relevant Chihuahua variants in one targeted analysis package.
• The result separates clear, variant-carrying and very unusual double-variant patterns, supporting selection and risk management.
• In dogs with compatible skin signs, the test provides genetic clarity for a complex skin phenotype that can resemble other dermatological conditions.
• For breeding plans, the result helps reduce risky combinations and unexpected loss of offspring linked to X-linked lethality.